Add notes about accepting masked arrays to hist

dstansby · dstansby · commit c4b9364e78ea · 2017-11-14T20:10:13.000Z
diff --git a/doc/users/next_whats_new/2017-11-09_hist-ignores-nans.rst b/doc/users/next_whats_new/2017-11-09_hist-ignores-nans.rst
@@ -4,3 +4,5 @@ Histogram function now accepts nan values in input
 The `~.Axes.hist` function now accepts nan values in both the *data* and
 *weights* input. Previously this would just error. Now any invalid values
 are simply ignored when calculating the histogram values.
+
+In addition, masked arrays are now valid input for both *data* and *weights*.
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -5893,7 +5893,9 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
         ----------
         x : (n,) array or sequence of (n,) arrays
             Input values, this takes either a single array or a sequence of
-            arrays which are not required to be of the same length
+            arrays which are not required to be of the same length.
+            Masked arrays or arrays with invalid values (e.g. ``nan``) are
+            allowed.
 
         bins : integer or sequence or 'auto', optional
             If an integer is given, ``bins + 1`` bin edges are calculated and
@@ -5949,7 +5951,8 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
             only contributes its associated weight towards the bin count
             (instead of 1).  If *normed* or *density* is ``True``,
             the weights are normalized, so that the integral of the density
-            over the range remains 1.
+            over the range remains 1. Masked arrays or arrays with invalid
+            values (e.g. ``nan``) are allowed.
 
             Default is ``None``
 
